1. Field of the Invention
The invention relates to a flame sensor and, more particularly, to a flame sensor having a sealed housing.
2. Discussion of the Prior Art
Within an oil or gas fueled turbine, fuel is fed into a combustion chamber within which an ignition flame is present. If the flame becomes extinguished, commonly referred to as a flame-out condition, it is undesirable for fuel to continue to be fed into the hot combustion chamber without appropriate ignition. A flame sensor is generally used for detecting the presence or absence of an ignition flame within a combustion chamber of a gas turbine. Flame sensing electronics are commonly associated with the flame sensor and may be exposed to a wide range of temperatures, such as in the range of 25° Celsius (77° Fahrenheit) to about 150° Celsius (302° Fahrenheit). Due to these temperature fluctuations, a housing that houses the flame sensing electronics will exhibit thermal expansion, causing leakage and allowing for the ingress of moisture. This moisture adversely affects the flame sensing electronics and, thus, reduces the accuracy of the flame sensor.
Accordingly, it would be useful to provide a flame sensor having a sealed housing that limits moisture from entering and affecting the flame sensing electronics at elevated temperatures.